Having originally announced that it would carry Apple’s new iPhone 4S on its WCDMA networks on February 21, China Telecom has today officially started selling the smartphone across its 2,850 retail outlets, having received more than 200,000 preorders within the last week.

The smartphone can be ordered on the Apple China Store or via China Telecom’s website and sees China Telecom become the second official carrier of the iPhone in the country, ending China Unicom’s 18-month exclusive partnership with Apple.

Whilst China Unicom launched the smartphone on January 13, China Telecom had to wait nearly two months to receive regulator approval to sell the device. Apple’s decision to utilise a dual-mode baseband ensured that it would not have to manufacture a separate device to operate on both frequencies, ensuring that when operators received approval, they could immediately stock supplies of the smartphone.

MICGadget reports that orders in Beijing and Shanghai have already exceeded 10,000 units and 20,000 units respectively, much more than the operator originally expected. China Telecom stocks the complete range of iPhone smartphones, in 16GB, 32GB and 64GB variations, with pricing starting at $0 RMB on select contracts.

Today’s launch means that the world’s biggest mobile carrier, China Mobile, is the only major Chinese operator not to offer the iPhone to its customers.

However, thanks to the ‘worldphone’ capabilities of the iPhone 4S, China Mobile still has over 15 million iPhone users, all of which use an unlocked iPhone on the carrier’s 2G networks, as a result of its network incompatibility with the handset.